Water-tube boiler



Oct. 29, 1929. BURKHARDT 1,733,644

WATER TUBE BOILER Filed Jan. 15. 1926 f 2 a 3 I llwenlbr Patented Oct. 29, 1929 UNITED STATES PATENT OFFICE GOTTLOB BURKHARDT, OF HERRENALB, GERMANY, ASSIGNOR TO JULIUS M. BURK- HARDT, JOHN FRED. BUBKHABDT, AND LANCE NICHOLSON, ALL OF BUFFALO, NEW

YORK

WATER-TUBE BOILER Application filed January 15, 1926, Serial No. 81,552, and in Germany January 16, 1925.

, bored water tube boilers adapted for use with high pressures, and it is intended to devise means of overcoming and eliminating p the difliculties which result from unequal bending and differences of strain in the seva eral tubular elements and in their connecting means with the chambers and with the upper and lower drums of the boiler. In the chambered water tube boilers or sectional boilers with clusters of straight water tubes arranged between parallel sections, chambers 1 [or compartments, as heretofore constructed, great clifliculties are experienced with the high efliciencies and high pressures now gen-' erally employed in View of the unequal heating andunequal extension in the several tubes and the consequent excessive high pressure in the axial direction of the tubes exposed to higher temperatures, while other tubes in the vicinity thereof, butwith lower tempera- 'ture are exposed to a'very high tensional strain in the axial direction. As a result thereof, either the tubes become loosened I and displaced at their points of connection with thechambers or compartments, 'or the 3o tubes which are heated to a relativelyv higher temperature are subject to a very serious bending strain by the influence of the excessive axial pressure. .This difficulty is particularly noticeable in I that kind of well known sectional boilers in which the vertically disposed clusters of ascending and de- 7 scending tubes are connected. at their lower ends with one andthersame chambeig while their upper ends areconnected to separate 40 to the upperboiler or drum of the system.

l/Vhile with moderate operating pressures and 7 moderate interior temperatures these difli :cult-ies, though notic'eable, are not particuhigh pressures the rigidity of connection of the, clusters of tubes causes a very serious danger for the safety of the boiler; In'order to overcome these difficulties, sectional water tube boilers have been suggested in which chambers which, if required, may be joined f larly serious and very dangerous, yet with curved water tubes, some of which with their straight terminal portions arranged in axial alinement, are disposed betweenparallel chambers or compartments, but with this construction of boilers there is the dif-. ficulty that the water tubes, though somewhat resilient, in view of their relatively deep and irregular curvature, cannot be inserted in the apertures of the chambers opposite their ends, nor withdrawn therefrom, and that it is not possible to properly clean such tubes in the manner readily applicable in the case of the ordinary straight water tubes between parallel chambers or boilers.

'N ow, in View thereof, it is one of the im.-. portant objects of my invention to dispose the water tubes between upper and 'lower boilers, chambers or compartments in parallel relation to each other in such a manner that every tube, in view of its peculiar bend, is free to extend and contract, without exerting any excessive tensional strain on the neighboringtubes, and is yet adapted to be readily inserted through the connecting holes in the boilers'or chambers opposite the tube ends and to be withdrawn therefrom, while, at the same time, presenting no difliculty to the required interior cleaning of the tubes. This object is accomplished in my invention, broadly speaking, by so arranging the curvature of the water tubes that they are bent in conformity with the line of bending stress of a hypothetical rod or beam secured at both of its ends and guided in the original straight axis of the tube, when under compression, the resulting curvature being sufliciently gentle or of sufficiently small degree as to allow of the tubes being withdrawn through the connecting openings in the chambers or boilers opposite the ends of the tubes while at the same time permitting the tubes to contract and expand and flex laterally as required under service temperatures and pressures.

While with this arangement of water tubes in sectional boilers chambers may be used in combination with one or more upper boilers or drums, it becomes possible to so combine the flexible water tubes with parallel and spacedly arranged chambers in chambered irate fro u p oth r, and hy thislmeaus a iti be e e p re e b e in ewe id e e h invention, to provide an uninterrupted continuous circulation of the water -whilel-the generated steam and the replenishing Water sponding ,there o il -may he Withdrawn from and respectively introduced into the 1 main. oir eulatingieurrent'in a separate xoycle. iThe nenticalztubeboilers earth upperidruanrand lo er iohamhers connecting :thebottornends rot the ascendinguandi descendingutuhes 1f modified according ito any; inrenrtionabm lthe combination with Water UlLbBSJllGIltfllllilflC- cordanre l with the zline iof :bendi-ng stress, 1 he fore, ;::become radaptedw r110; be uisedomth ;h g pressures and itor high 1 elfieieucres by eitherproyidingthe upperldrum theme-lian nerynnanner with itlie :walls let the atuhes in 1 parallel tep-arisearelatao aanclzinuparallelerec se, the 11 1 1 6 "holes theauuper drum re so arrange tha hei cent es tare em lt e axi l ali ement w 'fihx'hhfi lower stneig lends f the pipe er tub s, QiLSfiO :admitref a a lat ral twist 'fl nibl e m e ttuhe "onasaid straigh u xis. Further advan ages o the r invention -W1ll app ar from x-the speeifi atiemundermine ubodiment e t e principles o theiinmention cal tub boilenhau g g oup-ref ascen ing and. 1e group; of cleseemling tubes Wl a tu .connec ionhetween-th sameet h rest p :plenishinez eed Water is iutrhdu ejcl ma n ec rculating current zbyxrbhe pipes- -9l l 1Q; thence thevwater 'eurr n fiews-it he d en ing: "tubes and into-ether e r superpessd upper-(boilers. Fig. 21 isle front Vie f hea us rof wat rtubes. 1

As appears -trom, Fig "=11, itheaehemhees 1? the lascendang group of tubes "land; iorthe descending greup 2 are arranged, parallel to each other and the upper -chambers 3, as W l as the lower chambers-14, a e, Qennec ed y comparatively hmad-tuhesrto eaohotheu; th y m y, f urse, r-e so h made in -oneupiece or integral "with each .other. 'I-hemain coir-a cu tingcur ent; rises i thes-useendinggtub s 1, passes "through the cham er :13 i and th 31 g 1- l 6 cond t d hr ug the teem n ln -5 r 7, into the upper boilers 11, 12, While: free nto the rough group of as ending itu esl The-yupperlehempreterably disposed in axial alinement with each other and the curvature of the tubes iris-i ESQ aarrwgeduthatuit mill .corre po d 0 the line ofbending stress of an originally stuaightrbarzuneleriloadg the v bend zbeingicom- 1r aratiwelytgentlezandlamrangedrso astoimenge ugraclually nto theitemninalt apflfliitms LQill; the rctrrhes. In miemoi tlmis-ieonstruotion the tubes Moan :be 'reasi-ty aswizthdnmwn through: the icon -:meeting:rholesaofxtheq clrambers1:.opposite; athe yrpipe ends and; Ina-y'lheieleaned thnmlghith holes; Hlhelbendref these'zwaterztuhes is, rh'QWV- ever, i sutlficientlyilangee-aslrto allow 10i mach ztuheusbemg iadapted ratoeexpanduaml erespeq l ltixzeliy become rshontenedl as a resul 1 oil? a i l zinereaselormeductiorr of lengfihwithout there- .ulayexertin anyenadmissiblyslargeipressu :grxtensionrirhshmin 0.11 :themallsanfathechem- .HEI'S.v .r l a a Eff Thei -water'tubesrzaarliw ged andrleumai r stl umanner descrihedita and brilligiszflna td 111 a w iewrofe :thBiI'r'BIIdSill I ingr ldisposedwinnexi l i refinement; rpnesentmherfnrfrhercimmrtunha arwantagethet alieyzlmayabeatu tncd lletemlly i therlelitrpn ighuanekaltematinglm,ishdesirred, r on:eoneeanel'imhei-isame axisase s-t-mtfby -'-th meflnstil'lhelcwiil uknownehealiingpplmflfifiall y ileeaoanrieelvout with tubes constixurtedramnrdrdngslto rinyaentionpin":Whiuhl process the sa as onnnentsraneneompllad toiintersect-iea ot-her? tmioeiiat least, smas-moiprodm uery horoaglhiwhinling aroundlandiniterm ng'li g l of 'theheating'guses andmwer-y; SIIbSllflHlhifllliIlenease of fiieieney midi-superior rtnansmission osh-heart. l p l a "While the-invention has been shown'rand describedherein with'refienenpe to apreffierred embodiment thereof, itshowldhe understood 3 that its I 5piinbiples winay expression iiiother embodiments andemodi 'ficat ions so as tobetter adaptthe' invention to varying conditions' of applicationand without deviating froniits scope and spirit, aspartieularlyde "fined 'inithe"app'endd claiml" this nonxiect on it rmeyfberpointed; o x tha the upper .ehemhers may be rep a directly rhyiith upper. bo lers Lee ."by gene of th re which are lp eterably.arranged fin 11 ra @1191. relati n torthezilowe .vchambers. fl

centres, of thenonnecting holesafor the inserwtloniof the: tuheserepretenehly iuaaxialaalinenin mth-uthe.zloweri'temninal partso athe u es. a a

In an upright water tube boiler, a circulatory system comprising highly and less highly heated sets of ascending and descending curved water tubes, parallelly arranged headers directly connecting the upper and the lower ends of the tubes to eachother, water and steam containing means above the upper headers, one of said upper headers being arranged below the level of the other, tubes connecting the headers, tubes directly connecting the water and steam containing means with the upper header arranged at the higher level, and tubes connecting the water and steam containing means with the tubes connecting the upper headers at a point between said headers.

In testimon whereof I aflix m signature.

OTTLOB BUR DT. 

